Merge pull request #4384 from dokku/cron-trigger

Add support for injected cron entries from external plugins

docs/development/plugin-triggers.md

@@ -309,6 +309,40 @@ set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 curl "http://httpstat.us/200"
 ```
 
+### `cron-write`
+
+- Description: Force triggers writing out cron entries
+- Invoked by:
+- Arguments:
+- Example:
+
+```shell
+#!/usr/bin/env bash
+
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+
+# TODO
+```
+
+### `cron-entries`
+
+- Description: Allows injecting cron entries into the written out scheduled cron task list. Each entry is newline delimited, and individual entries come in the form `$SCHEDULE;$FULL_COMMAND;$ARBITRARY_DATA`. Individual implementations of cron writing can decide whether and how to include these cron entries. The `ARBITRARY_DATA` includes the log file path for the basic `docker-local` cron implementation.
+- Invoked by:
+- Arguments: `$DOKKU_SCHEDULER`
+- Example:
+
+```shell
+#!/usr/bin/env bash
+
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+
+DOKKU_SCHEDULER="$1"
+
+# TODO
+```
+
 ### `dependencies`
 
 - Description: Used to install system-level dependencies.

plugins/20_events/cron-entries

@@ -0,0 +1 @@
+hook

plugins/20_events/cron-write

@@ -0,0 +1 @@
+hook

plugins/cron/.gitignore

@@ -2,5 +2,6 @@
 /subcommands/*
 /triggers/*
 /triggers
+/cron-*
 /post-*
 /report

plugins/cron/Makefile

@@ -1,5 +1,5 @@
 SUBCOMMANDS = subcommands/list subcommands/report
-TRIGGERS = triggers/post-delete triggers/post-deploy triggers/report
+TRIGGERS = triggers/cron-write triggers/post-delete triggers/post-deploy triggers/report
 BUILD = commands subcommands triggers
 PLUGIN_NAME = cron
 

plugins/cron/functions.go

@@ -4,11 +4,11 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"html/template"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
+	"text/template"
 
 	appjson "github.com/dokku/dokku/plugins/app-json"
 	"github.com/dokku/dokku/plugins/common"
@@ -17,10 +17,23 @@ import (
 )
 
 type templateCommand struct {
-	ID       string
+	ID         string
-	App      string
+	App        string
-	Command  string
+	Command    string
-	Schedule string
+	Schedule   string
+	AltCommand string
+	LogFile    string
+}
+
+func (t templateCommand) CronCommand() string {
+	if t.AltCommand != "" {
+		if t.LogFile != "" {
+			return fmt.Sprintf("%s &>> %s", t.AltCommand, t.LogFile)
+		}
+		return t.AltCommand
+	}
+
+	return fmt.Sprintf("dokku --rm run --cron-id %s %s", t.ID, t.App, t.Command)
 }
 
 func fetchCronEntries(appName string) ([]templateCommand, error) {
@@ -86,11 +99,7 @@ func deleteCrontab() error {
 }
 
 func writeCronEntries() error {
-	apps, err := common.DokkuApps()
+	apps, _ := common.DokkuApps()
-	if err != nil {
-		return deleteCrontab()
-	}
-
 	commands := []templateCommand{}
 	for _, appName := range apps {
 		scheduler := common.GetAppScheduler(appName)
@@ -106,6 +115,30 @@ func writeCronEntries() error {
 		commands = append(commands, c...)
 	}
 
+	b, _ := common.PlugnTriggerOutput("cron-entries", "docker-local")
+	common.Log(fmt.Sprintf("output: %s", string(b)))
+	for _, line := range strings.Split(strings.TrimSpace(string(b[:])), "\n") {
+		if strings.TrimSpace(line) == "" {
+			continue
+		}
+
+		parts := strings.Split(line, ";")
+		if len(parts) != 2 && len(parts) != 3 {
+			return fmt.Errorf("Invalid injected cron task: %v", line)
+		}
+
+		id := base64.StdEncoding.EncodeToString([]byte(strings.Join(parts, ";;;")))
+		command := templateCommand{
+			ID:         id,
+			Schedule:   parts[0],
+			AltCommand: parts[1],
+		}
+		if len(parts) == 3 {
+			command.LogFile = parts[2]
+		}
+		commands = append(commands, command)
+	}
+
 	if len(commands) == 0 {
 		return deleteCrontab()
 	}
@@ -119,7 +152,7 @@ func writeCronEntries() error {
 		return err
 	}
 
-	tmpFile, err := ioutil.TempFile(os.TempDir(), fmt.Sprintf("dokku-%s-%s", common.MustGetEnv("DOKKU_PID"), "CopyFromImage"))
+	tmpFile, err := ioutil.TempFile(os.TempDir(), fmt.Sprintf("dokku-%s-%s", common.MustGetEnv("DOKKU_PID"), "WriteCronEntries"))
 	if err != nil {
 		return fmt.Errorf("Cannot create temporary schedule file: %v", err)
 	}

plugins/cron/src/triggers/triggers.go

@@ -18,6 +18,8 @@ func main() {
 
 	var err error
 	switch trigger {
+	case "cron-write":
+		err = cron.TriggerCronWrite()
 	case "post-delete":
 		err = cron.TriggerPostDelete()
 	case "post-deploy":

plugins/cron/templates/cron.tmpl

@@ -2,5 +2,5 @@ PATH=/usr/local/bin:/usr/bin:/bin
 SHELL=/bin/bash
 
 {{ range $entry := .Commands -}}
-{{ $entry.Schedule }} dokku --rm run --cron-id {{ $entry.ID }} {{ $entry.App }} {{ $entry.Command }}
+{{ $entry.Schedule }} {{ $entry.CronCommand }}
 {{ end -}}

plugins/cron/triggers.go

@@ -9,3 +9,8 @@ func TriggerPostDelete() error {
 func TriggerPostDeploy() error {
 	return writeCronEntries()
 }
+
+// TriggerCronWrite force updates the cron file for all apps
+func TriggerCronWrite() error {
+	return writeCronEntries()
+}

tests/unit/cron.bats

@@ -5,9 +5,20 @@ load test_helper
 setup() {
   global_setup
   create_app
+  mkdir -p /var/lib/dokku/plugins/available/cron-entries
+  mkdir -p /var/lib/dokku/plugins/enabled/cron-entries
+  cat >"/var/lib/dokku/plugins/available/cron-entries/plugin.toml" <<EOF
+[plugin]
+description = "dokku test cron-entries plugin"
+version = "0.0.1"
+[plugin.config]
+EOF
+  cp /var/lib/dokku/plugins/available/cron-entries/plugin.toml /var/lib/dokku/plugins/enabled/cron-entries/plugin.toml
+
 }
 
 teardown() {
+  rm -rf /var/lib/dokku/plugins/available/cron-entries /var/lib/dokku/plugins/enabled/cron-entries
   destroy_app
   global_teardown
 }
@@ -99,6 +110,69 @@ teardown() {
   assert_output_contains "python task.py second"
 }
 
+@test "(cron) injected entries" {
+  echo "echo '@daily;/bin/true'" > /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+  chmod +x /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+
+  run /bin/bash -c "dokku plugin:trigger cron-write"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
+
+  run /bin/bash -c "cat /var/spool/cron/crontabs/dokku"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output_contains "@daily /bin/true"
+
+  # log file
+  echo "echo '@daily;/bin/true;/var/log/dokku/log.log'" > /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+  chmod +x /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+
+  run /bin/bash -c "dokku plugin:trigger cron-write"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
+
+  run /bin/bash -c "cat /var/spool/cron/crontabs/dokku"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output_contains "@daily /bin/true &>> /var/log/dokku/log.log"
+
+  # specify matching scheduler
+  echo "[[ \$1 == 'docker-local' ]] && echo '@daily;/bin/true'" > /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+  chmod +x /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+
+  run /bin/bash -c "dokku plugin:trigger cron-write"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
+
+  run /bin/bash -c "cat /var/spool/cron/crontabs/dokku"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output_contains "@daily /bin/true"
+
+  # specify non-matching scheduler
+  echo "[[ \$1 == 'kubernetes' ]] && echo '@daily;/bin/true'" > /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+  chmod +x /var/lib/dokku/plugins/enabled/cron-entries/cron-entries
+
+  run /bin/bash -c "dokku plugin:trigger cron-write"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
+
+  run /bin/bash -c "cat /var/spool/cron/crontabs/dokku"
+  echo "output: $output"
+  echo "status: $status"
+  assert_failure
+}
 
 template_cron_file_invalid() {
   local APP="$1"